back now to the search for fired lapd police officer, christopher dorner. kyung lah has obtained footage. it shows he knows how to handle a weapon well. >> reporter: christopher dorner, lapd cadet in 2005. what do you think, watching this, considering what's happened? >> well, he's an expert with weapons. definitely. he's definitely dangerous. >> reporter: this man spent months with dorner at the lapd training academy. we are altering his voice and not showing his face, because he fears dorner will go after his police friends. but he wants the public to see this, so people understand what the lapd is facing. >> if you look at chris, you can see that he's a little bit of an expert. watch how he disarms the shoot. almost no movement when he shoots the gun, and then pop, like nothing. >> reporter: so he stood out. >> yeah, he stood out. he knew what he was doing. the lapd has -- they're going to be going after one of their own former, and he knows -- like i say, he knows what he's doing. he knows how to use everything. >> reporter: being a cop, do you think th